Supporters of the besieged bank enraged conservatives earlier this month by deploying a rarely used legislative tactic to force a vote in the House — expected next week — to restore the bank’s congressional charter, which lapsed over the summer.

The maneuver, known as a discharge petition, is likely to result in House approval of reauthorization despite fierce opposition from the GOP’s conservative wing, which views the financing provided by the bank for private-sector projects overseas as a corporate welfare.Expected passage of Rep. Stephen Fincher’s (R-Tenn.) bill would put the ball squarely in McConnell’s court.

The Kentucky Republican, who has said he personally opposes Ex-Im, has been reluctant to move legislation in the busy upper chamber, even as Sen. Mark Kirk (R-Ill.) used another procedural tool, known as Rule 14, to bring a reauthorization bill to the floor.

“The Senate is not going to spend a week on a bill that the leader doesn’t support,” Don Stewart, a spokesman for McConnell, told The Hill this week.

At the same time, it is widely believed that, as in the House, there are enough votes to approve reauthorization legislation, which enjoys almost universal support among congressional Democrats.

Sources in the business community believe McConnell would prefer Ex-Im supporters to attach a rider renewing the bank’s charter to legislation that extends the federal highway transportation fund, set to expire Oct. 31.

Rep. Maxine Waters (D-Calif.), the top Democrat on the House Financial Services Committee, however, said that the highway bill remains “the alternative choice” to a stand-alone bill.

“I really believe we can get a stand-alone bill in the Senate,” she said. “And I believe that it will come to the House and we’ll vote on it.”

It’s a political headache for McConnell, who faces dueling pressure from conservatives and from a larger number of senators — not to mention powerful business groups — who support the bank.

“He has to pick his poison — a stand-alone [bill] would enrage the Tea Party,” said one source working to reauthorize the bank. “But trying to put it on the highway bill may cause him to get rolled by his Senate colleagues.”

The source suggested that inclusion of a reauthorization measure in a larger piece of legislation might mean it “could get crippled and essentially killed again in a conference deal.”

The uncertainty surrounding the federal highway bill has supporters of the bank anxious that they might be left waiting yet again for another opportunity to reauthorize the bank, even if the Ex-Im language is attached.

Veronique de Rugy, an Ex-Im critic and scholar at George Mason University’s Mercatus Center, said the Senate majority leader is in “no better position” than outgoing Speaker John Boehner (R-Ohio), who faced the same pressures before announcing his retirement last month.

“McConnell and Boehner both have been willing to accommodate the Democrats — sometimes over the objections of a majority of the majority in the name of showing that Republicans can govern,” she said.

McConnell, however, could also view the Ex-Im fight as a bargaining chip in spending fights expected to dominate the upper chamber in the upcoming weeks and months.

Critics of the bank are hopeful that the more time that passes, the harder it will be to resurrect Ex-Im.

The bank’s charter lapsed June 30, meaning that bank officials are no longer able to extend new financing. However, bank officials can still make do on their commitments — some of which extend for more than a decade into the future.

Conservatives have argued that the bank is too political and opts to finance big corporations such as Boeing and General Electric as opposed to small businesses. Leading business groups argue that the bank sustains millions of jobs.